Sterilization of containers

ABSTRACT

A process and apparatus for continuously sterilising aseptically filling and closing containers, in which each successive container is dosed with a quantity of a sterilising agent which is retained within the container for a sufficient time for sterilisation to take place, is conveyed through a tunnel within which a gaseous environment under slight overpressure is maintained, and is filled and has a sterile lid applied under sterile conditions within the tunnel.

United States Patent Muys et al. 1451 Aug. 19, 1975 STERILIZATION OFCONTAINERS [56] References Cited [75] Inventors: Gerard Tuynenburg Muys,UNITED STATES PATENTS Ronerdam; Hubert lmnal'dus 3,291,563 12/1966Martin 21/58 x M ria L li vel M l Robert 3,401,043 9/1968 Finley et a1van der Hulst, Vlaardingen, all of 3,576,594 4/1971 Knetemann et al21/58 X Netherlands [73] Assignee: Lever Brothers Company, New PrimaryEa'mer T raVis Mcc'ehee York Attorney Agent. or F1rmArn0ld Grant, Esq.

22 F] d: l .1973 1 June 2 57 ABSTRACT [21] Appl NO': 369348 A processand apparatus for continuously sterilising Related US. Application Dataaseptically filling and closing containers, in which 3] c i q n f s[31,626, April 6 each successive container is dosed with a quantity of21 I97 I, abandoned. sterilising agent which is retained within thecontainer for a sufiicient time for sterilisation to take place, is [52]US. Cl i. 53/21 FC; 21/58; 53/22 R; conveyed through a tunnel withinwhich a gaseous en- 53/l ll RC; 53/110 vironment under slightoverpressure is maintained, [51] Int. Cl. B65b 55/10 and is filled andhas a sterile lid applied under sterile [58] Field ofSearchm53/2l FC. 2|R, 22 R, l l l RC. n i ion i hin the tunnel.

53/ll0. 112 R; 21/58 PATENTEU AUG'! 9 I975 SiiCET 1 BF 2 PATENTEI] AUG 191975 STERILIZATION OF CONTAINERS This application is acontinuation-in-part of our copending application Ser. No. l3l,626 filedApr. 6, 197], now abandoned.

The invention relates to a process and apparatus for sterilising,aseptically filling and closing containers by means of sterilisingagents such as gases. By sterilisation of the containers is alsounderstood, besides the killing ofeg. Bacillus and Closteridium spores,the specific killing of certain groups of microorganisms, e.g.osmophilic moulds and yeasts.

According to one aspect of the present invention a process is providedfor continuous sterilising, aseptically filling and closing containers,in which each successive container is dosed with a quantity ofasterilising agent which is retained within the container for asufficient time for sterilisation to take place, is conveyed through atunnel within which a gaseous environment under slight overpressure ismaintained, and is filled and has a sterile lid applied under sterileconditions within the tunnel.

sterilisation may also take place within the tunnel to reduce any riskof contamination during the sterilising process from the ambientatmosphere.

Advantageously the lid may be formed from a strip of foil which issterilised within the tunnel.

To accelerate the optimum sterilisation of particu' larly the insidesurfaces of the containers and in order to minimise on the use ofsterilising agent, each container may temporarily be sealed subsequentto dosing with the sterilising agent and during sterilisation so as tomaintain the sterilising agent within the container duringsterilisation, after which the temporary sealing is removed to allowfilling.

According to another aspect of the invention an apparatus for carryingout the above mentioned process comprises a tunnel which is arranged toenclose a gaseous environment under slight overpressure. a closingdevice for dosing a quantity of a sterilising agent into successivecontainers, a conveyor passing through said tunnel and arranged toconvey successive containers past the dosing device to allowsterilisation and through the tunnel, and means located within thetunnel for the filling and for the application ofa sterile lid to eachsuccessive container under sterile conditions.

The sterilising means may be arranged within the tunnel, so thatsterilisation takes place within this tunnel. The lid applying means maycomprise a strip of foil which is located and sterilised within thetunnel. To derive optimum result from the dosing of and to preventwasting of sterilising agent, the apparatus may be provided withtemporary sealing means for the temporary sealing of each successivecontainer after dosing with the sterilising agent to maintain thesterilising agent within the container during sterilisation.

The temporary sealing means may be composed of a strip of foil which isarranged to be pressed over the mouth of each successive containerduring sterilisation. A blowing means may be provided for generating anair current to press the foil over the mouth of each successivecontainer during sterilisation.

The foil can also be pressed over the mouths of the containers by meansof a block of elastic material.

The present apparatus may also be provided with a second conveyorparallel to the first conveyor and arranged to convey an endless stripof material resistant to the sterilising agent and keeping this strippressed over the mouth of each successive container duringsterilisation, while the speed of the second conveyor being arranged tomatch that of the containers on the first conveyor.

The sterilising agent may conveniently but not necessarily be hydrogenchloride mixed with air and satisfactory sterilisation times can beachieved if the partial pressure of hydrogen chloride is from about 0.5mm Hg to about several atmospheres, preferably above 50 mm Hg, and mostpreferably above I00 mm Hg, at a temperature preferably between 5C and40C. A partial pressure of hydrogen chloride of from I20 mm Hg to I40 mmHg, especially a partial pressure of about mm Hg, has been found to beparticularly satisfactory. At these partial pressures of hydrogenchloride it is generally necessary, in order to avoid condensation onthe surface to be sterilised, which condensation is undesirable becauseit may damage the surface or materials subsequently in contact with thesurface, to reduce the partial vapour pressure of the water vapour inthe air below that which occurs naturally. These partial water vapourpressures can be determined from the literature, eg from theInternational Critical Tables (F. C. Zeisberg, W. B. van Arsdel, F. C.Blake, C. H. Greenewalt and G. B. Taylor, International Critical Tablesof Numerical Data, Physics, Chemistry and Technology, Vol. III, 1st Edn.National Research Council, New York, l928 From the foregoing it will beappreciated that dry hydrogen chloride alone could be used forsterilisation and this would generally involve a pressure equal toatmospheric. When more rapid sterilisation is required, hydrogenchloride at superatmospheric pressures may be used e.g. at sixatmospheres. In such cases the advantages of rapid sterilisation mayoutweigh in practice the disadvantages of complicated construction toprevent the escape of hydrogen chloride gas.

It is in practice generally necessary to purge or flush thesterilisation apparatus and the containers, the surfaces of which are tobe sterilised, with an inactive dry gas to remove all ambient air whichis generally sufficiently humid to produce local condensation on contactwith hydrogen chloride gas at the partial pressures under consideration.Practical considerations in some cases require the containers aftersterilisation to be flushed with an inactive dry sterile gas to removetraces of hydrogen chloride in and around the containers, which tracesof hydrogen chloride could be objectionable during subsequent storage.

When a supply of inactive dry sterile gas has to be available, it isgenerally more economical to use gaseous hydrogen chloride mixed withthis gas, after adjusting the water vapour content of this gas, toprovide the sterilising gas mixture, and also to use this gas forflushing the apparatus and containers.

It has also surprisingly been found that for water vapour partialpressures between zero and those which will cause condensation, there isa minimum partial water vapour pressure above which microorganisms arekilled more quickly than they are below it. This is a new and surprisingdiscovery since it was generally believed that there was a steadyincrease in rate of killing microorganisms as the partial water vapourpressure increased from zero to the point where condensation occurs.This critical partial water vapour pressure has been found to be betweenl mm and L5 mm mercury, and appears to be substantially independent ofthe partial vapour pressure of hydrogen chloride.

The partial water vapour pressure of the mixture of hydrogen chlorideand inactive dry gas (which conveniently is air and is hereafterreferred to as air) used to sterilise containers in accordance with thepresent invention may be adjusted as follows:

I. The humidity of the ambient air is measured,

2. Ambient air is mixed with substantially dry air, e.g. from thereduction valve of a compressed air bottle, (e.g. internal pressureinitially 100 atmospheres), both streams of air passing throughbacterial filters being chosen to give the required partial water vapourpressure, Le. a partial water vapour pressure between about 1 mm mercuryand that at which condensation arises at the temperature of operation.The resulting sterile air of predetermined partial water vapour pressureis referred to as conditioned air"; air" as indicated above being usedherein to include the use of any inert gas besides air.

3 Conditioned air and hydrogen chloride gas are then mixed together togive the desired partial pressure of hydrogen chloride gas.

The air from a normal commercial compressed air bottle, after throttlingdown to atmospheric pressure has a negligible partial water vapourpressure, since it will be approximately the quotient of the saturatedwater vapour pressure at any given temperature (compressed air bottlesalways contain free water), and the pressure, in atmospheres, inside thebottle.

When a larger supply of air is required, it is conveniently supplied bya pump and passes through a drier which is essentially a refrigeratingunit where with the compressed air may be cooled to a controllabletemperature, thereby condensing and removing excess water. Thereafterthe air passes through a microbiological filter and is mixed in meteredproportions with hydrogen chloride gas from commercial cylinders.

More specifically, therefore, the present invention comprises a processfor the continuous sterilisation of solid surfaces of articles,particularly the surface of foodstuff containers, at a temperaturepreferably between 5C and 40C, wherein the articles undergo continuouslyand successively a first flushing treatment where ambient air is andaround the articles is flushed away with a blast of dry inert gas, asterilising treatment where the articles are exposed to hydrogenchloride gas, preferably hydrogen chloride mixed with 0.5 conditionedair wherein the hydrogen chloride has a partial pressure from 0.5 mm Hgto one atmosphere, immedi ately followed by a second flushing treatmentwhere conditioned air is used to flush away from the articles any tracesof hydrogen chloride gas.

When employing a mixture of ambient air and air from a compressed airbottle it is generally desirable to have the partial water vapourpressure of the conditioned air some fraction, say 50, 70 or 80 percent,of that at which condensation occurs, so that there is some margin forvariation in the water content of the ambient air between ambientair-humidity determinations.

in a preferred manner of operation which is particularly suited to givethe best results when sterilising plastic containers for foodstuff, thearticles (containers) are subjected to a dust-removal treatment withionised air prior to the first flushing treatment to accelerate theremoval of dust, and the exteriors of the containers are subjected to aneutralising treatment after the second flushing treatment to neutraliseany hydrogen chloride adsorbed on the external surfaces of thecontainers. The object of this neutralising treatment is to preventdesorption of the absorbed hydrogen chloride during storage, sinceotherwise, in the case of storage of large quantities of containers,this desorption of hydrogen chloride could produce in the atmosphere ofthe storage space undesirably high concentrations of hydrogen chloridegas. The hydrogen chloride gas absorbed in the interior of thecontainers is so small that it is generally absorbed by the foodstuffsubsequently placed in the container without any noticeable effect onthe foodstuff especially if the foodstuff is naturally acid.

in apparatus for carrying out the process of the present invention, thearticles are conveniently moved continuously by means of a conveyordisposed substantially horizontally, through a number of zones orenclosures corresponding to the successive treatments indicated aboveand wherein these treatments are carried out. It is preferred,especially when the articles to be treated are plastic food containers,to provide the conveyor with openings of a shape corresponding closelyto the upper part of the containers, so that the latter have a more orless gas-tight fit in the conveyor. in this way the contact of theexterior of the containers with hydrogen chloride gas is reduced to aminimum.

For safety reasons the apparatus may be provided with an outer casingenclosing said tunnel and retaining round the tunnel a surroundingjacket of a gaseous atmosphere which is kept under a slightunderpressure.

Containers sterilised, filled and sealed by means of the above mentionedprocess are included in the invention.

The invention will now be further illustrated with ref erence to thedrawing, in which:

FIG. 1 is a schematic cross-section of an apparatus according to theinvention with temporary sealing foil;

FIG. 2 is a cross-section of another construction of the apparatuswithout temporary sealing means;

FIG. 3 is a cross-section of a third embodiment of the apparatusprovided with a double encasing and temporary sealing means;

FIG. 4 is a part longitudinal sectional elevation of a preferred type ofapparatus without temporary sealing means.

FIG. 5 is a part transverse sectional elevation on the line VV of HO. 4and shows means for applying an alkaline solution to the exterior ofsterilised containers.

The process and apparatus to be further described now are particularlysuitable for so-called cold sterilisation. The sterilising agents usefulin this respect include e.g. gaseous hydrogen halides, in particular hy'drogen chloride, ethylene oxide, ethylene imine, C1 and maybe theseagents in gaseous form or maybe gases evaporating from the liquid state.

A tunnel is particularly advantageous in this invention since itprovides a convenient enclosure in which the environment can be keptunder the required conditions for a continuous process.

In the figures, 1 denotes a conveyor, here in the form of an endlessconveyor belt (not completely shown) of a material determined by thechoice of the sterilising gas, e.g. coated metal or PVC. This conveyorserves to convey the containers 2 to be sterilised and filled, the

containers passing under a dosing device 3 for dosing either ajet ofundiluted sterilising gas or a microdroplet of a gas-generating liquid.The dosing device is connected to a photo-electric cell by means of anauxiliary circuit. which assembly permits the dosing of a small,reproducible amount of the sterilising agent. e.g. hydrogen chloride gasor a concentrated hydrochloric acid solution, into each open containerat the moment that it passes under the nozzle 3. In a reliability testof more than 40,000 dosings, which was faultlessly performed in glassjars having a neck opening of 6!) mm, speeds were obtained of 70jars/min or 4,200 jars/h.

After closing the required amount of the sterilising agent, thecontainers should preferably be kept closed by a temporary sealing meansfor a certain time, in order to effect optimum sterilisation of theinside surfaces and in order to prevent wasting of sterilising agent.

The temporary sealing operation may be effected in various ways. A foil4 of material resistant to the gas used can be made to extend over thecontainer openings. For this purpose a number of materials can be used.For the present application polyethylene foil, polypropylene foil orPTFE (Teflon) were used. In order to enable renewal of this material, incase of possible wear owing to contact with the containers passing underit, the foil is led from a supply roller 5 to an uptake-roller 6.

The foil can be kept pressed over the mouths of the containers duringthe sterilisation period by means of a blowing device 7, generating asterile air current. which is divided by a divider 8 over the foilsurface to be blown as shown in FIG. 1. The divider 8 is shown in moredetail in FIG. 3.

The temporary sealing operation can also be achieved by pressing thefoil over the mouths of the containers during sterilisation by means ofa block of elastic material (not shown in drawing). Finally, this isalso possible by means of a second conveyor which conveys an endlessstrip of material resistant to the sterilising agent, e.g. impermeablePVC-foam. The ro tating speed of the strip should in this case match,i.e. be substantially equal to that of the containers on the firstconveyor belt. This embodiment is not illustrated in the drawing either.

When leaving the strip of covering-material as shown in FIG. 1, thecontainers on the conveyor should immediately come into a tunnel 9, inorder to prevent infec tion. It is preferred to accommodate the wholeplant in a tunnel, also indicated by 9 in FIGS. 2 and 3, which by meansof a predetermined mixture of air, and a sterilising gas is kept under aslight excess pressure. In this case the blowing device 7 can as well beused to supply the mixture which keeps the whole space under the slightexcess pressure (FIG. 2), as retain its function of blowing the foil(FIG. 3). The enclosed tunnel 9 preferably is provided with an entranceand exit device 12 (FIGS. 2 and 3). which may have any desired construction. The air used for the mixture in the sterilising space should havea relative moisture content such that no condensation of the sterilisingagent can occur. When no temporary sealing means are used, as shown inFIG. 2. it is preferred to have blowing device 7 near the exit of theapparatus. This is done in order to avoid turbulence around thecontainers at the beginning of the sterilisation process. whichturbulence could cause still live spores to be blown out of thecontainers e.g. to-

wards the filling device. For masons of safety the apparatus shouldadditionally be surrounded by an outer casing 13 within which a slightunder-pressure is permanently maintained, so that any escapingsterilising gas is exhausted at 14 to a safe place.

The tunnel may be subdivided into separated compartments, e.g. wheredifferent compartments need diffcrent gaseous environments.

Dependent on the kind of product to be filled in the container and itscompatibility with the sterilising agent it may be desirable to wash outeach successive container after sterilising and prior to filling, e.g.by means of a jet of sterile air.

Before the dosing of the filling mass begins. the whole tunnel 9 and thedevice I0 are to be sterilised, preferably with hydrogen chloride gas.For the sterilisation of the sealing material of the containers 2 usecan be made of steam or hydrogen peroxide. HCl gas also being preferredfor this purpose.

The containers 2, shown in FIG. I as glass jars, are sealed withsterilised lids, as indicated schematically at 11, and subsequentlydischarged from the apparatus by the conveyor belt.

The containers 2 indicated in FIGS. 2 and 3 may eg be cups of syntheticmaterial, which may have to be placed into supporting moulds 15. It isschematically shown how these cups are provided with closure from a foilI7 and sealed by means of sealing device 16. As indicated at IS, thefoil may be additionally sterilised with a jet of hydrogen chloride gasbefore the dosing operation.

Turning now to FIG. 4, a conveyor belt 44 driven by a motor 45 conveysplastic beakers 46 of the type used for yoghurt from a delivery point 47through a first flushing zone 48, a sterilisation zone 49, a secondflush ing zone 50 to filling and closing devices 51 and 52, whichdevices are indicated diagrammatically since their detailed constructiondoes not form part ofthe present invention, The conveyor belt 44 is anendless flexible belt of material resistant to hydrogen chloride, e.g.PVC reinforced with polyester gauze, or a glass fibre fabric impregnatedwith PFTE. At regular intervals along this belt are fixed plates 53 ofhard plastic material, e.g. hard PVC or polyester. These plates raveprojections or teeth 54 engaging respectively ving and idling sprockets55, 56 and also have openi s 57 registering with openings 58 in the belt44, whic penings have an internal profile adapted to fit closely roundthe upper parts of the beakers 46 as :Jhown in FIG. 5. By havingopenings of varying internal profiles, the conveyor belt 44 may be niadeto handle beakers of varying shapes and sizes. By having the beakersfitting closely in the openings 58 and edges of the flexible belt 44having rubbing contact with outwardly projecting flanges 60 forming partof a machine frame 61 (see FIG. 5 the penetration of hydrogen chloridegas to the lower side of the upper run of the belt 44 is reduced to aminimum. Inwardly projecting flanges 71 support the teeth 54.

At the delivery point 47 the beakers are released from a stack of nestedbeakers and fall into the openings 58. Known means, such asphotoelectric means, are provided to ensure that each ring receives aproperly positioned beaker, or to give a signal, or stop the conveyor 44is a beaker if missing from an opening or improperly placed therein. Aroller 62 ensures that the beakers are securely seated in the openings58 with flanges at the tops of the beakers overlapping the upper edgesof the openings.

in a first flushing zone 48, a jet of dry air is directed through pipe63 into the interior of a beaker 46 to remove the ambient air therein. Avent 64 allows the outflow of air from this zone and the arrangement ispreferably such that a gauge pressure of 0.05 mm H O is maintained inthis zone. Thereafter the beakers pass through the sterilisation zone 49which is fed via supply line 65 with the required mixture of hydrogenchloride gas and air and a water gauge pressure of 0.32 mm is maintainedon this zone. It will be noted that the beakers 46 move incounter-current to the flow of sterilising mixtures.

The beakers next pass to the second flushing zone 50 wherein a pluralityof nozzles 66, supplied with dry sterile air from a chamber fed bysupply line. A vent line 67 allows the escape of a mixture offlushing-air and sterilising mixture.

The beakers are finally filled at SI and closed at 52, e.g. withsterilised foil lids, and ejected by an ejection device 68. whereuponthey pass to storage.

Under the conditions indicated above it has been found satisfactory forthe beakers to be for 30 seconds in the sterilising zone 49 and 12seconds in the second flushing zone 50.

FIG. 5, also shows inlet pipes 69 whereby an alkaline fluid. e.g. anaqueous solution of sodium bicarbonate, may be sprayed around theexternal surface of the beakers 46 after they have left the closingdevice 52.

We claim:

I. A process for continuously sterilizing, aseptically filling andclosing containers in a low-moisture environment maintained atsubstantially ambient conditions comprising the steps of subjecting thecontainers to a first flushing treatment wherein dry gas movesrelatively to said containers to flush away ambient air in and aroundsaid containers, subsequently subjecting the containers to a sterilizingtreatment wherein said containers are sterilized by the action ofhydrogen chloride gas, subjecting the containers to a second flushingtreatment wherein conditioned air moves relatively to said containers toremove free hydrogen chloride from the surface thereof, filling thecontainer, effecting a sterile closure of said containers andsubstantially removing from the external surface hydrogen chlorideabsorbed thereon.

2. A process as claimed in claim I, in which the external surfaces ofthe containers are subjected to a treatment with an agent whichneutralizes the hydrogen chloride absorbed thereon.

3. A process according to claim 1, in which the external surfaces of thecontainers are sprayed with an alkaline solution.

4. A process according to claim 1, in which the external surfaces of thecontainers are flushed with an inactive gas.

S. A process as claimed in claim I, in which a mixture of hydrogenchloride gas and conditioned air is used in the sterilising treatmentand the partial pressure of the hydrogen chloride gas is at least I00 mmHg.

6. A process as claimed in claim I, in which the sterilising treatmentis carried out in 30 seconds.

7. A process as claimed in claim 1, in which the dry gas used in thefirst flushing treatment is conditioned air.

8. A process as claimed in claim I, in which prior to the first flushingtreatment, the containers are subjected to a stream of ionised air toremove dust from the surfaces of 9. A process as claimed in claim 1, inwhich after the second flushing treatment, the containers are sprayedwith an alkaline solution to neutralise hydrogen chloride adsorbed onthe exterior surfaces of said containers.

10. A process for continuously sterilising, aseptically filling andclosing containers in a low moisture environment maintained atsubstantially ambient conditions comprising the steps of placing thecontainers on a moving conveyor; moving the containers past asterilising agent dosing device; dosing the containers with asterilising agent which does not substantially increase the temperatureof the container; temporarily sealing the container; retaining thesterilising agent in the container for a time sufficient forsterilisation to take place; moving the containers into a sterile tunnelwithin which a gaseous environment is maintained at slight overpressure; removing the temporary seal; filling the container; applying asterile lid to the container; and moving the closed container out of thetunnel.

II. An apparatus for continuously sterilising, aseptically filling andclosing containers in a low moisture environment maintained atsubstantially ambient conditions comprising a sterilising agent dosingdevice which delivers a measured amount of a sterilising agent into thecontainers; means to temporarily seal the container after dosing withthe sterilising agent; the sterilising agent being retained in thecontainer for a time sufficient to sterilise them without substantiallyincreasing the temperature of the containers; a sterile tunnel withinwhich a low moisture gaseous environment is maintained at slightoverpressure, said tunnel containing means to remove the temporary seal,to aseptically fill the containers and means to emplace a sterile lid onthe containers; and, a conveyor for receiving the containers and movingthem serially past the sterilising agent dosing device, the fillingmeans, the lid emplacing means and out of the tunnel.

12. An apparatus according to claim 1, in which the temporary sealingmeans comprises a strip of foil which is arranged to be pressed over themouth of each succesive container during sterilisation.

. i I i i l

1. A process for continuously sterilizing, aseptically filling andclosing containers in a low-moisture environment maintained atsubstantially ambient conditions comprising the steps of subjecting thecontainers to a first flushing treatment wherein dry gas movesrelatively to said containers to flush away ambient air in and aroundsaid containers, subsequEntly subjecting the containers to a sterilizingtreatment wherein said containers are sterilized by the action ofhydrogen chloride gas, subjecting the containers to a second flushingtreatment wherein conditioned air moves relatively to said containers toremove free hydrogen chloride from the surface thereof, filling thecontainer, effecting a sterile closure of said containers andsubstantially removing from the external surface hydrogen chlorideabsorbed thereon.
 2. A process as claimed in claim 1, in which theexternal surfaces of the containers are subjected to a treatment with anagent which neutralizes the hydrogen chloride absorbed thereon.
 3. Aprocess according to claim 1, in which the external surfaces of thecontainers are sprayed with an alkaline solution.
 4. A process accordingto claim 1, in which the external surfaces of the containers are flushedwith an inactive gas.
 5. A process as claimed in claim 1, in which amixture of hydrogen chloride gas and conditioned air is used in thesterilising treatment and the partial pressure of the hydrogen chloridegas is at least 100 mm Hg.
 6. A process as claimed in claim 1, in whichthe sterilising treatment is carried out in 30 seconds.
 7. A process asclaimed in claim 1, in which the dry gas used in the first flushingtreatment is conditioned air.
 8. A process as claimed in claim 1, inwhich prior to the first flushing treatment, the containers aresubjected to a stream of ionised air to remove dust from the surfaces of9. A process as claimed in claim 1, in which after the second flushingtreatment, the containers are sprayed with an alkaline solution toneutralise hydrogen chloride adsorbed on the exterior surfaces of saidcontainers.
 10. A process for continuously sterilising, asepticallyfilling and closing containers in a low moisture environment maintainedat substantially ambient conditions comprising the steps of placing thecontainers on a moving conveyor; moving the containers past asterilising agent dosing device; dosing the containers with asterilising agent which does not substantially increase the temperatureof the container; temporarily sealing the container; retaining thesterilising agent in the container for a time sufficient forsterilisation to take place; moving the containers into a sterile tunnelwithin which a gaseous environment is maintained at slight overpressure; removing the temporary seal; filling the container; applying asterile lid to the container; and moving the closed container out of thetunnel.
 11. An apparatus for continuously sterilising, asepticallyfilling and closing containers in a low moisture environment maintainedat substantially ambient conditions comprising a sterilising agentdosing device which delivers a measured amount of a sterilising agentinto the containers; means to temporarily seal the container afterdosing with the sterilising agent; the sterilising agent being retainedin the container for a time sufficient to sterilise them withoutsubstantially increasing the temperature of the containers; a steriletunnel within which a low moisture gaseous environment is maintained atslight overpressure, said tunnel containing means to remove thetemporary seal, to aseptically fill the containers and means to emplacea sterile lid on the containers; and, a conveyor for receiving thecontainers and moving them serially past the sterilising agent dosingdevice, the filling means, the lid emplacing means and out of thetunnel.
 12. An apparatus according to claim 1, in which the temporarysealing means comprises a strip of foil which is arranged to be pressedover the mouth of each succesive container during sterilisation.